This study is designed to determine if a 24hr infusion of GHRP will result in increased or attenuated GH secretion. In addition, the GH response to an IV bolus dose of GHRP or GHRH at the end of the infusion will be determined. If the effect is specific to GHRP (and is not seen with GHRH) this will indicate that the receptor is down-regulated, and that the response is mediated through receptors other than that of GHRH.